ICoupler® number isolator is used extensively at spanning to keep apart bar to transmit digital signal. Below certain circumstance, digital isolator also can drape the pony armour of n converter unexpectedly in be not segregation application, n is offerred to change a function in the system!

 

Is isolator of number of the ICoupler® in be not segregation application how to offer n to change a function? We will treat two conditions:

 

Circumstance one: Power source of –48 V DC-DC

 

In application of communication power source, standard report course is –48 V dc, and signal of former margin control is reference with this report course. Signal of deputy margin control is the low voltage I/O(that is reference with the ground normally for example, + 5 V, + 3.3 V CMOS) . Former border district and deputy border district are linked together, whole system keeps apart type to be not. In application of power source of this kind of DC-DC, digital isolator suits to offer n to change a function for feedback signal.

 

Graph 1. The –48 V that is based on digital isolator to take feedback comes power source of 5 V DC-DC

 

If the graph is shown 1 times, the tall n of deputy edge inputs voltage to be 5 V, low n voltage is 0 V; The tall n voltage of former edge is –43 V, low n is –48 V. The course of report of –48 V of join of former border district of digital isolator, and –43 V of join of VDD power source. Because the buy inside existence keeps apart bar, the each edge of isolator works inside independent voltage region, provided the function that n changes. Isolator of use ICoupler number still can protect deputy edge circuit not to suffer breakdown to affect, if pass,be pressed or short circuit.

 

Circumstance 2: System of much power source

 

To the system of region of much power source, the likelihood has one or more power source to be in close position and other power source is in working status. Below this kind of circumstance, if be between area of two power source,put in any data line join, involve area likelihood with parasitism means by data on-line voltage or voltaic power supply. Graph 2 showed case of this kind of application. If want to avoid discharge leakage current, must set digital line for low n output or tall impedance mode.

 

 

Graph 2. Between region of two power source divulge electric current

 

When isolator of use ICoupler number replaces region of two power source to join directly, but the discharge leakage current that block breaks meantime (graph 3) . Because need not control output state right now, because this can simplify,the protection of hardware and software is designed.

 

 

Graph 3. Use number isolator joins area of two power source